1. Field of the Invention
This invention relates to a removable locking device for maintaining a union between two conduits. The locking device forms an engagement with the two conduits and a union nut connecting the conduits to substantially prevent disengagement of the union during use.
2. Description of the Relevant Art
Frequently, manufacturing processes require fabrications of piping for carrying, e.g., chemical reactants, waste streams, or fluids for heating and cooling. For purposes of this application, a "fabrication" is an assembly of a plurality of sections of piping. The sections of piping need not be the same length. In an embodiment, a fabrication may be a substantially linear structure including sections of substantially straight piping. Alternatively, a fabrication may include sections of piping having curved portions and/or bends of various angles formed therein. In still another embodiment, a fabrication may include both substantially straight and curved or bent sections.
In a conventional type of end-to-end joint for two conduits, the end of one conduit is provided with an external threading and the end of the other conduit is provided with a lip or flange. The flange can be abutted by a lip of a union nut so that axial drawing together of the two conduits may be obtained by tightening the union nut onto the threaded conduit portion. A resiliently compressible seal element, such as an O-ring, may be placed between the end faces of the respective portions to form a fluid-tight engagement between the conduit sections.
The piping often carries hazardous materials (e.g., corrosive, caustic or toxic materials). Often, the materials are also heated to very high temperatures. Such piping may also be used for steam or hot water. As such, it is imperative that leaks not form in the unions so that workers may be protected from accidental exposure to the hazards. Further, a leak of even non-hazardous materials, such as chilled water from a cooling line, may damage expensive processing equipment (e.g., by causing an electrical short) and shut down a processing line, resulting in significant economic losses.
As such, it is desirable to ensure that unions between conduits will not come apart due to, e.g., vibration, expansion, or contraction of the conduits and the union nut or accidental jostling of the union by a worker. It is preferred to weld the conduits upon installation to prevent union failure. Welding, however, may not always be possible. For example, the spacing between neighboring (e.g., parallel or adjacent) conduits may be such that welding is impractical or prohibited. Therefore, it would be desirable to implement an alternative means of ensuring that unions between conduits are maintained during use.